Doctoral Dissertation Research: A 1,200-Year, High-Resolution Record of Hurricane Activity for Southern New England

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

The present record of the natural variability of hurricane activity is insufficient to accurately predict the recurrence intervals for hurricane catastrophe events. The study of coastal sedimentary sequences that provide long-term proxy records of hurricane activity can be used to address this issue. This doctoral dissertation research project will develop a 1,200-year-long high-resolution record of hurricane and tropical storm activity for the Boston area based primarily on the sedimentary record from the Lower Mystic Lake. The Mystic Lake record is laminated and appears to hold an annually resolvable archive of sedimentation for the last millennium. Hurricane storm surge and overwash events can be detected in the sediments by changes in physical sedimentology and diatom assemblages. Based on microscopic examination of the laminae and radiometric dating, this project will develop a high-resolution record of these events for the region over the last millennium. The record will be compared with a lower-resolution record developed from a marsh in Boston Harbor. This second record is more typical of studies carried out elsewhere to reconstruct past hurricane frequency. It is expected that the Mystic Lake record will preserve more subtle events and events that are closely spaced in time, occurrences that are not evident in a lower-resolution record. The project will contribute to understanding of how synoptic climate controls may moderate different regional modes of hurricane activity. By examining the frequency of hurricane events in the context of long-term climate changes, in particular the frequency of events over the past millennium from the cold episodes of the "Little Ice Age" compared to warmer periods, results of the project may suggest the expected hurricane activity in a climate warmed by greenhouse gases. The value of better understanding hurricane activity and recurrence intervals is enhanced by populations that have led increasing numbers of people to live along or near coastlines that are subject to hurricanes. More than half of the total U.S. population currently is located in vulnerable coastal zones, and these populations are expected to swell another 20 percent by 2015. Combined with the uncertainty of how global warming may affect hurricane activity, civic planners, disaster management agencies, and the global insurance industry have begun to wonder whether recent disasters like Hurricane Andrew are simply a precursor to an increasing number of even more costly and deadly tropical storms in the coming decades. Results from this project will contribute to the growing body of knowledge necessary to answer this question. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.